Conventionally, a vane type vacuum pump which is used as a vacuum pump for a car is known (Patent Literature 1). The conventional vacuum pump is configured to provide lubrication oil to a sliding part of a rotor which rotates in pump room of the housing and the lubrication oil after lubrication at the sliding member is discharged with gas through discharge passage to outer part of the pump room with rotation of the rotor.
In this vane of the vacuum pump, a cap sliding on the inner surface at the rotation is attached. The cap is pressed to the housing at the rotation of the vane and constructed to seal between the surface of the housing and the vane (for example, it is described in the Patent Literature 1 and in the Patent Literature 2.).